The Facts About Bull Sharks In Freshwater - We Love Sharks!
"Bull sharks inhabit quite shallow waters, which means that they do have a great . Freshwater tolerance could be rooted in competition for saltwater food Get up close to a shark feeding frenzy and meat-eating bats in these. But lines are kinda blurred in tidal environment, say a delta is a mix between freshwater and And a spiecies known as bullshark is commonly found in freshwater, sometimes further than How can sharks live in freshwater and saltwater?. Seven Fish Species That Can Survive In Both Fresh And Salt Water possible for a bull shark to spend the entirety of its life in freshwater, most.
The process of osmoregulation accomplishes this.
The Facts About Bull Sharks In Freshwater
In sharks, the normal mechanism of osmoregulation in a marine salt environment is the high concentration of urea and other biological solvents in their blood and the removal of excess salt from their bloodstream through urine.
The former allows them to absorb water from their marine surroundings, while the latter rids them of the salt they continually absorb. These tasks are primarily controlled by the kidneys. In most sharks, these adaptations cannot be changed.
If they are put into a freshwater environment, they will absorb too much water relative to their concentration of bodily solvents and lose too much salt to stay alive. In other words, most sharks cannot survive in fresh water because they are not capable of adapting to it. Bull sharks are unusual because they can adapt readily to fresh water because they can adapt their process of osmogregulation.
The kidneys of bull sharks, and to a lesser extent several other types of sharks can be gradually adjusted to suit the salinity of the water they are in. When moved gradually into freshwater perhaps by migrating from the ocean, to an estuary, and then upriverbull sharks' kidney's remove less salt and more urea from the bloodstream through urination, essentially reversing the normal marine shark method of osmoregulation.
This adaptation allows bull sharks to live entirely in estuaries or freshwater. Bull sharks are regularly sighted in Lake Nicaragua some live there permanently and have been reported 2, miles from the ocean in the Amazon River. Heres a little background.
Water balance is critical for all living things. Animals that live in salt water have to make sure they have enough fresh water in their tissues.
To understand how this works, lets talk about a process called osmosis. Water is attracted to things like salts, proteins, and such. If we have a membrane that allows water but not the dissolved salts and stuff to pass through, water will tend to go to the side where the salts are.
Cell membranes leak water, so if you put a cell into salty water, the fresh water in the cell will leave. The cell gets dehydrated and cant survive. Salt water fish keep their outside somewhat waterproof, but salt comes in through their gills and when they eat.
So they have to do other things to protect themselves. First, they have kidneys that are good at taking the salt out of the blood and putting it into urine. The kidneys also hold onto urea the waste product made from breaking down proteins.
Shark Savers :: How Bull Sharks Survive in Fresh Water
They also have rectal glands that can remove salt from the body. Keeping urea, proteins, and other things dissolved in their blood attracts water in from the outside. This makes the water part of the sea water come in, while leaving the salt behind. Sharks keep just enough stuff dissolved in their body to equal out the concentration of the sea water.
All of this would be a problem for a shark that you suddenly dropped into freshwater. Fresh water would flow into the shark, attracted by the urea, salts, proteins, and such. This would kill the shark due to cell damage and the fact that some of the chemicals in the sharks body would be diluted too much to do their jobs.